技術標籤：JavaJava框架javamybatis

目錄

0、增加100條catgory資料

1、修改Category.xml

2、測試

3、註解方式

4、參考連結

0、增加100條catgory資料

為了觀察分頁查詢的效果，把分類表裡的資料都刪除掉，然後新增100個數據

package com.how2java;
    
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
 
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 
import com.how2java.pojo.Category;
    
public class TestMybatis {
    
    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();
        List<Category> cs = session.selectList("listCategory");
        for (Category c : cs) {
            session.delete("deleteCategory", c);
        }
        for (int i = 0; i < 100; i++) {
            Category c = new Category();
            c.setName("category name " + i);
            session.insert("addCategory", c);
        }
        List<Category> cs2 = session.selectList("listCategory");
        for (Category c : cs2) {
            System.out.println(c.getName());
        }
 
        session.commit();
        session.close();
 
    }
}
 

1、修改Category.xml

新增limit

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 
    <mapper namespace="com.how2java.pojo">
        <insert id="addCategory" parameterType="Category" >
            insert into category_ ( name ) values (#{name})   
        </insert>
         
        <delete id="deleteCategory" parameterType="Category" >
            delete from category_ where id= #{id}  
        </delete>
         
        <select id="getCategory" parameterType="_int" resultType="Category">
            select * from   category_  where id= #{id}   
        </select>
 
        <update id="updateCategory" parameterType="Category" >
            update category_ set name=#{name} where id=#{id}   
        </update>
        <select id="listCategory" resultType="Category">
            select * from   category_
                <if test="start!=null and count!=null">
                    limit #{start},#{count}
                </if>
        </select>    
    </mapper>
 

2、測試

用註解方式再做一遍
注：start是指從第0個開始，如果是第二頁，那麼就是第5個開始。
注：count引數是指每頁有5條資料

• CategoryMapper.java

package com.how2java.mapper;
  
import java.util.List;
 
import org.apache.ibatis.annotations.Many;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
 
import com.how2java.pojo.Category;
  
public interface CategoryMapper {
    public List<Category> list();
    public List<Category> listByPage(@Param("start") int start, @Param("count")int count);
}
 

• TestMybatis.java

package com.how2java;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 
import com.how2java.mapper.CategoryMapper;
import com.how2java.pojo.Category;
   
public class TestMybatis {
   
    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();
 
//        xmlWay(session);   
        annotationWay(session);
         
        session.commit();
        session.close();
    }
 
    private static void xmlWay(SqlSession session) {
        Map<String,Object> params = new HashMap<>();
        params.put("start", 0);
        params.put("count", 5);
        List<Category>  cs =session.selectList("listCategory", params);
        for (Category c : cs) {
            System.out.println(c);
        }
    }
 
    private static void annotationWay(SqlSession session) {
        CategoryMapper mapper = session.getMapper(CategoryMapper.class);
         
        List<Category>  cs =mapper.listByPage(0, 5);
        for (Category c : cs) {
            System.out.println(c);
        }
    }
     
}

3、註解方式

• CategoryMapper.java

package com.how2java.mapper;
  
import java.util.List;
 
import org.apache.ibatis.annotations.Many;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;
 
import com.how2java.pojo.Category;
  
public interface CategoryMapper {
    @Select(" select * from category_ ")
    @Results({@Result(property = "products", javaType = List.class, column = "id", 
          many = @Many(select = "com.how2java.mapper.ProductMapper.listByCategory"))})      
    public List<Category> list();
     
    @Select(" select * from category_ limit #{start},#{count}")
    public List<Category> listByPage(@Param("start") int start, @Param("count")int count);
}

• TestMybatis.java

package com.how2java;
   
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
 
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
 
import com.how2java.mapper.CategoryMapper;
import com.how2java.pojo.Category;
   
public class TestMybatis {
   
    public static void main(String[] args) throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
        SqlSession session = sqlSessionFactory.openSession();
 
        CategoryMapper mapper = session.getMapper(CategoryMapper.class);
         
        List<Category>  cs =mapper.listByPage(0, 5);
        for (Category c : cs) {
            System.out.println(c);
        }
        session.commit();
        session.close();
    }
}

4、參考連結

[01] How2j - MyBatis - 分頁